Marine pipe trencher



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`Filed. July l0, 3.956

T. R. LITTLE 2,875,585 MARINE PIPE TRENCHER 2 Sheets-Sheet l Ted R. L/ff/e INVENTOR.

March 3, 1959 Filed July l0, 1956 T. R. LITTLE MARINE PIPE TRENCHER 2 Sheets-Sheet 2 Ted l?. iff/e INVENTOR..

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l ing the marine pipe trencher in a trench forming United States Patent() MARINE PIPE TRENCHER Ted R. Little, Rockport, Tex. Application July 10, 1956, Serial No. 596,963

7 Claims. (Cl. 61-72) This invention relates in general to new and useful improvements in pipe laying mechanisms, and more specifically to an improved marine pipe trencher.

At the present time there has arisen a large demand for suitable equipment for laying pipes in trenches beneath the water. This is particularly true in the off shore oil eld areas where pipes are being laid from the wells to the shore or to other suitable points whereby the oil may be pumped into tankers. Inasmuch as the water is relatively shallow it is necessary that the pipes be disposed within trenches in order to prevent damage from wave action. Also, in other instances where ships anchors and the like may engage the pipes it is highly desirable that they be placed in trenches.

It is therefore the primary object of this invention to provide an improved pipe trencher which s suitable for marine use and which may be actuated by towing a pipe trencher for the tug or the like and requiring no control other than the alignment of the towing tug with the general direction of the pipe which is being laid in the trench, the marine pipe trencher being of such a construction whereby it may be mounted on the guided thereby.

Still another object of this invention is to provide an improved pipe trencher for marine operations, the pipe trencher being in the form of a simple sleeve which may be readily mounted on a pipe for movement therealong with the pipe guiding the sleeve, and a plow carried by the sleeve for digging into the earth and forming a trench simultaneous with the laying of the pipe in said trench.

Still another object of this invention is to provide an pipe being laid and improved marine pipe trencher which is `so `constructed whereby repeated passes may be made on a pipe so that the depth of the trench in which itis being laid may be increased to` that desired and the pipe is laid into the lower part of the trench after each pass of the pipe trencher.

A further object of this invention is to provide an improved` marine pipe trencher which includes a plow -for forming a trench, the plow being pivotally mounted on a guide sleeve of the pipe trencher whereby the direction of movement of the pipe trencher may be controlled and a trench may be formed in either direction of movement without removing a supporting sleeve from the pipe being laid,.the plow havingconnected thereto tow means for the pipe trencher whereby the plow is automatically positioned with respect to the sleeve by the direction of pull on the sleeve.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more Ifully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is atsectional View taken through a body of water in which a pipe is being laid and showing a tug tow- `and pipe laying operation;` 1

Figure 2 is an enlarged fragmentary sectional view taken through the lower part of the body of water and shows the pipe normally resting upon the bottom of the body of water in its initial position;

Figure 3 is an enlarged fragmentary sectional view similar to Figure 2 and shows a trench having been dug in the bottom of the body of water and the pipe lowered therein, the trench having been formed by the marine pipe trencher which is the subject of this invention;

Figure 4 is an enlarged elevational view of the pipe removed from the body of water and shows mounted thereon in solid lines the marine pipe trencher with the plow thereof positioned for movement from the left to the right, the marine pipe trencher also being shown in dotted lines and positioned for movement from right to left;

Figure 5 is an enlarged fragmentary plan view of the pipe and shows `further the details of the pipe trencher;

Figure 6 is an enlarged fragmentary sectional view taken substantially upon the plane indicated by the section line 6-6 of Figure 4 and shows the specic details of the sleeve of the pipe trencher and the relationship thereof with respect to the pipe, and also being shown the general outlines of a ground breaking plow mounted at opposite ends of the sleeve;

Figure 7 is an enlarged fragmentary longitudinal sectional view taken through the marine pipe trencher which shows the specific details of a main plow thereof and the relationship of'such plow with respect to the sleeve; and

Figure 8 is an enlarged fragmentary sectional view taken substantially upon the plane indicated by the section line 8--8 of Figure 7 and shows further the details of the main plow.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figure 1 a body of water 10 having a bottom 12. Initially resting upon the bottom 12 is a pipe 14 to be laid. Engaged on the pipe 14 for movement therealong is the marine pipe trencher which is the subject of this invention, the marine pipe trencher being referred to in `general by the reference numeral 16. The marine pipe trencher 16 is being towed by a tug 18 through the means of a suitable line 20 and is forming a trench 22 in which the pipe 14 is being laid.

The marine pipe trencher 16 includes an elongated sleeve which is referred to in general by the reference numeral 24. The sleeve 24 is of the split type and includes a pair of sections 26 and 28 which are pivotally connected together along upper edges by :a longitudinal hinge 30. In order that the halves 26 and 23 of the sleeve 24 may be retained in asleeve forming position, there is carried at each end of the section 26 a strap 32 which terminates in an ear 34. Also carried at each end of the half 28 is a strap 36 which terminates in an ear 38. The ears 34 and 38 are connected together by a suitable fastener 40 which is removable to permit pivoting of the halves 26 `and 28 away from each other to the dotted line positions of `Figure 6 to facilitate removal of the sleeve 24 from the pipe 14.`

In order to facilitate the sliding movement of the sleeve 24 over the pipe 14, the sleeve 24 is provided at opposite ends with conical portions 42. The conical portions 42 facilitate the entry of the pipe 14 into the sleeve 24. In order that dirt and other foreign matter entering into the sleeve 24may be removed therefrom, the halves 26 and 28 are provided with suitable` openings 44 at opposite ends thereof and a central opening 46.

In order to facilitate the breaking of the ground beneath the pipe 14 in the initial plowing operation, there is secured to the underside portion of the sleeve 24 at opposite ends thereof ground breaking plows which are referred to bythe reference numeral 48. Theground breaking plows 48 face in opposite directions and are generally V-shaped in conguration, as is best illustrated in Figure 6. The ground breaking plows 48 are formed in sections 50 with one -of the sections of each plow 48 being carried by one of the sleeve halves 26 and the other of the sections 50 being carried by the other of the sleeve halves 28. Thus the ground breaking plows 48 may be mounted at the bottom of the sleeve 24 for the most etective operation and at the same time permits the opening of the sleeve 24 for positioning over and removal from the pipe 14.

The marine pipe trencher 16 also includes a main plow which is referred to in general by the reference numeral 52. The main plow S2 is of the disk type and is concaved, as is best illustrated in Figures 7 and 8. The

' main plow 52 includes a disk-like body portion 54 which is provided at its center and on its underside with a depending ear 56. The ear 56 is pivotally carried by a transverse pivot pin 5S which is in turn carried by a pair of ears 6i) projecting upwardly from one of the halves of the sleeve 24. .Thus, the main plow 52 is mounted on the sleeve 24 for pivotal movement.

Referring now to Figure 7 in particular, it will be seen that there is provided a pair of longitudinally disposed trap doors 62 and 64 which are mounted on opposite sides of the center of the body member 54 and which are pivotally connected thereto by pivots 66 and 68, respectively. p

Disposed intermediate the trap doors 62 and 64 is a tow arm 70. The tow arm 70 is aligned with the ear 56 and projects away from the body portion 54. The tow arm 70 terminates at the end thereof remote from the body member 54 in an eye 72 through which the line passes whereby the marine pipe trencher 16 may be connected to the tug 18 for towing.

In Figure 7, the marine pipe trencher 16 is positioned for towing movement from left to right. When a towing force is placed upon the towing arm 70 it will assume the position of Figure 7, the angle of the towing arm 70 varying slightly depending upon the depth of the water 10. As the body member S4 pivots with respect to the sleeve 24, the sleeve 24 will engage the trap door 64 `and swing it to an open position. At the same time, the trap door 62 is urged to a closed position by the pressure of water and earth thereupon. As the marine pipe trencher 16 is towed from the left to the right in Figure 4, the right hand ground breaking plow 48 will break the ground and advance the main plow 52 and the main plow S2 will then form a trench of the desired width, such as the trench 22 of Figure 3.

Normally one pass of the marine pipe trencher 16 will not provide a trench of the desired depth. Rather than remove the marine pipe trencher 16 from the pipe 14, which operation would require a diver, and start the trenching operation all over again, the tug 18 is merely turned around so as to tow the marine pipe trencher 16 in the opposite direction. When the pull on the tow arm 70 is shifted, the tow arm 70 and the main plow 52 will pivot from the solid line position of Figure 4 to the dotted line position of the same figure. At this time the sleeve 24 will engage the trap door 62 and move it to an open position. At the same time, the pressure of water and earth on the trap door 64 will move it to a closed position, continued movement of the marine pipe trencher 16 to the left will result in the deepening of the trench 2,2. The process is repeated back and forth over the pipe 14 until such time as the trench 22 of the desired depth is dug. As each trench forming pass is made, the pipe 14 will be lowered into the trench.

In certain instances it may be desired to dig a trench 22 which is of a greater depth than the half height or the main plow 52. In order that the main plow 52 may b e guided in the trench which has already been formed, there is secured to the outer edge of the body member 54 a pair of verticallydisposed, parallel guide plates 74. The guide plates 74 are connected to the body member 5'4 along the horizontal diameter thereof. Thus as the main plow 52 moves downwardly into the trench 22, the guide plate 74 will engage the walls of the trench 22 and prevent the transverse shifting of the main plow 52 and the rest of the marine pipe trencher 16.

From the foregoing description of the present invention, it will be readily apparent that there has been devised a marine pipe trencher which is of a simple construction and which is so formed whereby it may be nepeatedly towed back and forth over a pipe with each pass of the marine pipe trencher being in the form of a trench forming pass so that trenches of the desired depth may be formed without removing the marine pipe trencher from the pipe.

It is pointed out at this time that the ground breaking plows 48 may be of various configurations depending upon the type of bottom 12 in which the trenching operation is being performed. However, only one type of ground breaking plow has been illustrated inasmuch as the ground breaking plows 4S will vary greatly depending upon the bottom.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

l. A machine for forming trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over a pipe, a ground breaking plow on the under side of said sleeve, and a main plow secured to said sleeve, said main plow projecting down on opposite sides of said sleeve and above said sleeve, and tow means for moving said sleeve, said ground breaking plow and main plow as a unit, said main plow being pivotally secured to said sleeve, said tow means being connected to said main plow for positioning said main plow relative to said sleeve during a trench plowing operation, said main plow having guide means at opposite sides thereof to guide said main plow in a trench being dug during subsequent plowing operations.

2. A machine for forming trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over a pipe, a ground breaking plow on the under side of said sleeve, and a main plow secured to said sleeve, said main plow projecting down on opposite sides of said sleeve and above said sleeve, and tow means for moving said sleeve, said ground breaking plow and main` plow as a unit, said main plow being pivotally secured to said sleeve, said tow means being connected to said main plow for positioning said main plow relative to said sleeve during a trench plowing operation, said sleeve being longitudinally split to facilitate engagement of said sleeve on a pipe.

3. A machine for forming a trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over 4a pipe, a plow, means pivotally mounting said plow on said sleeve for movement between oppositely directed operative positions, said plow projecting down on opposite sides of said sleeve below said sleeve, said plow also extending above said sleeve, and tow means connected to said plow for moving said plow to and retaining said plow in that operative position corresponding to the direction of movement of said sleeve imparted thereto by said tow means during a trench plowing operation.

4'. A machine for forming a trench under water and simultaneously positioning a pipe inthe trench, said lnia-L chine comprising an elongated sleeve for guided movement over a pipe, a plow, means pivotally mounting said plow` on said sleeve for movement between oppositely directed operative positions, said plow projecting down on opposite sides of said sleeve below said sleeve, said plow also extending above said sleeve, opposite trap doors in said plow in alignment with said sleeve facilitating clearance of said sleeve in both positions of said plow and at the same time providing a generally uninterrupted plow surface, and tow means connected to said plow for moving said plow to and retaining said plow in that operative position corresponding to the direction of movement of said sleeve imparted thereto by said tow means during a trench plowing operation.

5. A machine for forming a trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over a pipe, a plow, means pivotally mounting said plow on said sleeve for movement between oppositely directed operative positions, said plow projecting down ou opposite sides of said sleeve below said sleeve, said plow also extending above said sleeve, and tow means connected to said plow for moving said plow to and retaining said plow in that operative position corresponding to the direction of movement of said sleeve imparted thereto by said tow means during a trench plowing operation, said plow having guide means on opposite sides thereof to guide said plow in a trench having been dug during subsequent plowing operations.

6. A machine for forming a trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over a pipe, a plow, means pivotally mounting said plow on said sleeve for movement between oppositely directed operative positions, said plow projecting down on opposite sides of said sleeve below said sleeve, said plow also extending above said sleeve, oppositely directed ground breaking plows on the underside of said sleeve, said iirst mentioned plow being disposed intermediate said ground breaking plows, and tow means connected to said plow for moving said plow to and retaining said plow in that operative position corresponding to the direction of movement of said sleeve imparted thereto by said tow means during a trench plowing operation.

7. A machine for forming trench under water and simultaneously positioning a pipe in the trench, said machine comprising an elongated sleeve for guided movement over a pipe, a ground breaking plow on the underside of said sleeve, and a main plow secured to said sleeve, said main plow projecting down on opposite sides of said sleeve and above said sleeve, and tow means for maving said sleeve, said ground breaking plow and main plow as a unit, said main plow being pivotally secured to said sleeve, said tow means being connected to said main plow for positioning said main plow relative to said sleeve during a trench plowing operation, said main plow having opposite trap doors facilitating clearance of said sleeve in both positions of said main plow and at the same time providing a generally uninterrupted plow surface.

References Cited in the' le' of this-patent UNITED STATES PATENTS 2,144,063 Irvin Ian. 17, 1939 2,731,738 Kossa Jan. 24, 1956 2,795,111 Richardson June 11, 1957 

